FOR 668:  Datierte Speläotheme: Archive der Paläoumwelt

• Fachliche Zuordnung: Geowissenschaften
• Förderung: Förderung von 2005 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 16276678

• Erstellungsjahr: 2015

Zusammenfassung der Projektergebnisse

The goal was to understand the basic mechanisms which control speleothem growth and composition by a combined application of field and laboratory experiments. Speleothems should advance to a precisely dated continental archive providing quantitative climate information. Fundamental questions were: How much of the observed variability of stable isotope and other proxies in stalagmites are caused by physical and chemical processes in the caves, and how much of the signals represent variations of temperature and precipitation? In this context 14C studies and experimental work and monitoring of recent processes in different karstic environments were conducted to understand and model the CO2-cycle in the caves and the reconstruction of CO2 in caves. The potential of novel proxies in speleothems including noble gases as paleo-thermometer and, in the second phase, Mg isotopes as paleo-weathering indicator were investigated. The focus of the second phase of DAPHNE was on the generation of records and their interpretation in terms of paleoclimate variability applying the knowledge and the methods derived from the first phase of the project. A major question was, whether it is possible to reconstruct spatial and temporal variability of precipitation and temperature during the Holocene from speleothem records. A very important part in this context was the close collaboration with climate modelers. The comparison of the climate reconstruction from stalagmite proxies with the model output was conducted to reveal the pattern of climate variability on a larger scale as well as the influence of large scale processes like the North Atlantic Oscillation on Holocene European climate. The goal of the last phase was a synthesis of the natural Holocene Climate variability in Europe based on stalagmites studied during the DAPHNE project including data sets from Europe that are available in literature. These data are important basis for prognostic climate modeling. The outstanding results are presented in the Special Issue „Advances in understanding and applying speleothem climate proxies“, which was published in the international journal Climate of the Past. This Special Issue contains 16 peer review contributions of members of the FOR 668 and numerous international experts in the field. During the funding duration of the project we produced 88 publications in peer reviewed journals, and further scientific publications will follow. Young researchers in the field were educated. Eight PhD students finished their theses during the funding period.

Projektbezogene Publikationen (Auswahl)

• A re-evaluation of the palaeoclimatic significance of phosphorus variability in speleothems revealed by high-resolution synchrotron micro XRF mapping. Climate of the Past, 8, 2039-2051, 2012
  S. Frisia, A. Borsato, R. N. Drysdale, B. Paul, A. Greig, and M. Cotte
  
• Bunker Cave stalagmites: an archive for central European Holocene climate variability. Climate of the Past, 8, 1751-1764, 2012
  J. Fohlmeister, A. Schröder-Ritzrau, D. Scholz, C. Spötl, D.F.C. Riechelmann, M. Mudelsee, A. Wackerbarth, A. Gerdes, S. Riechelmann, A. Immenhauser, D.K. Richter, and A. Mangini
  
• Effects of dating errors on nonparametric trend analyses of speleothem time series. Climate of the Past, 8, 1637-1648, 2012
  M. Mudelsee, J. Fohlmeister, and D. Scholz
  
• Holocene climate variability in north-eastern Italy: potential influence of the NAO and solar activity recorded by speleothem data. Climate of the Past, 8, 1367-1383, 2012
  D. Scholz, S. Frisia, A. Borsato, C. Spötl, J. Fohlmeister, M. Mudelsee, R. Miorandi, and A. Mangini
  
• Simulated oxygen isotopes in cave drip water and speleothem calcite in European caves. Climate of the Past, 8, 1781-1799, 2012
  Wackerbarth, P. M. Langebroek, M. Werner, G. Lohmann, S. Riechelmann, A. Borsato, and A. Mangini
  
• The magnesium isotope record of cave carbonate archives. Climate of the Past, 8, 1849-1867, 2012
  S. Riechelmann, D. Buhl, A. Schröder-Ritzrau, D. F. C. Riechelmann, D. K. Richter, H. B. Vonhof, J. A. Wassenburg, A. Geske, C. Spötl, and A. Immenhauser
  
• Influence of orbital forcing and solar activity on water isotopes in precipitation during the midand late Holocene. Clim. Past, 9, 13-26, 2013
  S. Dietrich, M. Werner, T. Spangehl, and G. Lohmann
  
• Reconstruction of drip-water δ18O based on calcite oxygen and clumped isotopes of speleothems from Bunker Cave (Germany). Climate of the Past, 9, 377-391, 2013
  T. Kluge, H. P. Affek, T. Marx, W. Aeschbach-Hertig, D. F. C. Riechelmann, D. Scholz, S. Riechelmann, A. Immenhauser, D. K. Richter, J. Fohlmeister, A. Wackerbarth, A. Mangini, and C. Spötl
  
• Simulated European stalagmite record and its relation to a quasi-decadal climate mode. Climate of the Past, 9, 89-98, 2013
  G. Lohmann, A. Wackerbarth, P. M. Langebroek, M. Werner, J. Fohlmeister, D. Scholz, and A. Mangini
  
• Stable isotopes in caves over altitudinal gradients: fractionation behaviour and inferences for speleothem sensitivity to climate change. Climate of the Past, 9, 99-118, 2013
  V. E. Johnston, A. Borsato, C. Spötl, S. Frisia, and R. Miorandi